Structural unit



March 5, 1968 L. G. STURGILL 3,

STRUCTURAL UNI T Filed June 30, 1966 INVENTOR [ESTER 6. STURG/LL BY W 5M AGE/V T United States Patent 3,371,458 STRUCTURAL UNIT Lester G.Sturgill, Leeshurg, Va., assignor to Atlantic Research Corporation,Fairfax County, Va., a corporation of Virginia Filed June 30, 1966, Ser.No. 561,953 10 Claims. (Cl. 52-646) This invention relates generally tostructural units, and more particularly to structural units composed ofa plurality of interconnected sections of identical configuration, and a'tower constructed therefrom.

There are many applications for light-weight, easily assembled anderected towers for electronic emissions and the like. A preferred formof construction is of a plurality of individual structural units. Sinceit is advantageous to construct a tower of a plurality of identicalstructural units having a minimum of brace and fittings, many of theprior-art towers advance this concept, most setting forth a four-sidedbasic unit. A major problem with four-sided structural units, andconsequently with towers constructed therefrom, is that a four-sidedshape is not inherently rigid without the addition of crossbraces, andthe use of cross-braces defeats the idea of having identical memberswith few extra parts; thus the construction of the tower is greatlycomplicated.

Briefly stated, the instant invention presents an inherently rigid,easily assembled and disassembled structural unit of triangularconfiguration and a tower constructed using a plurality of such units.Each unit is readily assembled and disassembled and is composed of threeidentical sections. Each section comprises a hollow tube with a slotalong its entire length, a second hollow tube or solid rod of diameterless than that of the first hollow tube, and means for attaching theslotted tube and the rod together,such as a plurality of struts, asingle plate, or the like. The struts are welded between the tube androd to construct a rigid section and are attached to the slotted tube atan angular distance of 60 from the slot. A unit of the tower isconstructed of three sections by sliding the rod of each section intothe tube of an adjoining section such that the struts of the first passthrough the slot of the second. Each of the rods is parallel to, butlongitudinally slightly offset from the tube. A pin in the bottom ofeach hollow tube supports the rod, and when the second unit is placedupon the first, the rod protrudes up into the tube above to support theupper unit. Such a design facilitates the construction of a tower.

It is an object of this invention to provide a structural unit which isinherently rigid and easily assembled and disassembled.

Another object of this invention is to provide an erectable towerconstructed of a plurality of identical units which are easily andquickly assembled and disassembled.

Other objects and advantages of the present invention will be comeobvious from the following detailed description when considered with theaccompanying drawings, wherein:

FIGURE 1 is a side view in elevation of a single section of thestructural unit of the instant invention;

FIGURE 2 is a perspective view of three of the sections of FIGURE 1assembled to form the structural unit of the invention;

FIGURE 3 is a plan view of FIGURE 2;

FIGURE 4 is a perspective view of the of the units of FIGURE 2; and

FIGURE 5 is a perspective view of a means for raising the units ofFIGURE 2 to construct a tower.

As shown in FIGURE 1, a single section 7 of the structural unit consistsof a tube 10 having a slot 12 along its entire length. Spaced laterallyfrom the tube joining of two and parallel thereto is a rod 14 ofdiameter slightly less than tube 10. Although described herein as a rodthis particular element may also be a hollow tube and still be withinthe purview of the instant invention. Rod 14, although parallel to tube10, is not aligned longitudinally therewith but is offset a distance 16along the parallel axes. The reason for this offset 16 will hereinafterbe explained. To attach tube 10 to rod 14 there is shown a series ofstruts 18, which are welded at one end to tube It) at an angulardistance of 60 from the slot 12 and at the other end to rod 14. Althoughthese connecting members are shown as a series of struts, there could bea single member such as a plate, or various other arrangements of strutsor like supporting members. At the lower or offset portion, tube 10 canbe provided with at least two aligned poles 26 which are adapted toreceive a bolt or rod which will support rod 14 being inserted into tube10.

FIGURE 2 shows a complete structural unit 8 assembled from three of thesections described above, and FIGURE 3 a plan view of said unit. A unitis constructed by inserting rod 14 of one section into tube 10 ofanother section such that the struts 18 project through slot 12. Theaddition of a third element in like fashion completes the unit. Pins 22are then inserted through cooperating holes 20 to support each of therods 14 and thus a rigid inter-locking unit is provided. Holes 20 can,as an alternative not shown, he placed near the middle of tube It andthen rod 14 equipped with a cooperating hole such that tube 10 in rod 14can be pinned together. The offset of rod 14 from tube It) by distance16 provides that a section of each of the rods of the unit will protrudeabove the top of the tubes and therefore will fit into the lower portionof the tubes in the above section to interlock and provide support forthis upper unit.

In FIGURE 4 there are shown two juxtaposed structural units. Assembly ofan entire tower is provided by placing the offset portions of each ofthe rods 14 of one unit into the offset portion of the tubes 10 of theadjacent unit. If increased rigidity is necessary, a second series ofbolts 26 can be placed through a second set of aligned holes 28 in thebottom portion of tubes 10, these also going through a cooperating hole30 in the ofl set section of each of the rods 14.

A preferred means and method for constructing a tower is shown in FIGURE5. A tower launcher 34 of triangular shape is mounted on legs 36, and atower is constructed by pushing assembled structural units 8 up throughlauncher 34, fitting each new section in below as shown in FIGURE 4. Theuse of this method of erecting a tower is particularly advantageous whenin close quarters or in an environment such as a jungle in which a heavycover of foliage above the ground precludes more conventional erectingprocedures such as guy wires or cranes.

The structural unit provided by the instant invention is rigid and iseasily assembled. The fact that it consists of three identical elementsand a minimum of small parts adds to its attractiveness since it lessensthe difiiculties encountered in packing and shipping as well asminimizes the supervision and instruction necessary to those whoassemble the units on location. Each of the sections of the individualunit is of simple construction and is easily manufactured from stockparts. The use of the geometric form of a triangle means that thestructural unit is inherently rigid, in cross-section, and once thethree locking pins 22 are installed, all three sections '7 of unit 8 arerigidly locked against longitudinal movement and cannot be separateduntil the pins are removed. In addition, maximum ability to endure thestresses and strains of the types of loading encountered in towerconstructions is provided by the fact that each hollow tube has a rod 3or second tube inside to strengthen it and to prevent it from bendingand collapsing. The fact that the structural units interlock means thatexternal forces are smoothly and evenly transmitted throughout the unitand the tower.

Obviously many modifications and variations of the present invention arepossible in the light of teachings. It is, therefore, to be understoodthat in the scope of the appended claims the invention may be practicedotherwise than as specifically described.

What is claimed as new and desired to be secured as Letters Patent ofthe United States is:

1. A structural unit for building an elongated structure comprising afirst section, a second section, and a third section, all of saidsections being of identical configuration and each of said sectionscomprising:

a hollow tube having a first diameter,

a rod laterally spaced from and parallel to said tube, said rod having asecond diameter less than said first diameter,

a slot longitudinally aligned through said tube and traversing theentire length thereof, said slot having a width less than said seconddiameter,

means for attaching said rod to said tube, said means being fixedlyattached at one end to said rod and at the other end to said tube at anangular distance of 60 from said slot;

the rod of said first secion being inserted into the tube of said secondsection such that the attaching means of said first section pass throughthe slot of said second section; the rod of said second section beinginserted into the tube of said third section such that the attachingmeans of said second section pass through the slot of said thirdsection, and the rod of said third section being inserted in the tube ofsaid first section such that the attaching means of said third sectionpass through the slot of said first section.

2. A structural unit in accordance with claim 1 further comprising meansfor restricting movement of each of said rods with respect to said tubeinto which it is inserted.

3. A structural unit in accordance with claim 2 wherein said means forrestricting movement comprises bolt means extending through each of saidtubes.

4. A structural unit in accordance with claim 1 wherein said means forattaching said rod to said tube comprises a plurality of struts.

5. A structural unit in accordance with claim 1 wherein said rod andsaid tube are of equal length and said rod is offset longitudinally withrespect to said tube.

6. A structural unit in accordance with claim 5 further comprising meansfor restricting movement of each of said rods with respect to said tubeinto which it is inserted.

7. A structural unit in accordance with claim 5 wherein said means forattaching said rod to said tube comprises a plurality of struts.

8. A tower comprising a plurality of structural units in accordance withclaim 6, said units being assembled such that the offset portion of eachof said rods in one unit is inserted into the offset portion of each ofsaid tubes in another unit.

9. A tower in accordance with claim 8 further comprising means forlocking adjacent of said units together.

10. A tower in accordance with claim 9 wherein said means for lockingadjacent of said units together comprises pin means extending throughsaid offset portion of said rods and said ofiset portion of said tubes.

References Cited UNITED STATES PATENTS 2,308,832 1/1943 Roney et al.182178 XR 2,620,904 12/1952 Le Roy 52646 2,736,613 2/1956 Jagiel 52-6462,828,842 4/1958 Plumley et al. 16-171 3,070,234 12/1962 Deitchman287189.36 XR BOBBY R. GAY, Primary Examiner.

ANDREW M. CALVERT, Assistant Examiner.

1. A STRUCTURAL UNIT FOR BUILDING AN ELONGATED STRUCTURE COMPRISING AFIRST SECTION, A SECOND SECTION, AND A THIRD SECTION, ALL OF SAIDSECTIONS BEING OF IDENTICAL CONFIGURATION AND EACH OF SAID SECTIONSCOMPRISING: A HOLLOW TUBE HAVING A FIRST DIAMETER, A ROD LATERALLYSPACED FROM AND PARALLEL TO SAID TUBE, SAID ROD HAVING A SECOND DIAMETERLESS THAN SAID FIRST DIAMETER, A SLOT LONGITUDINALLY ALIGNED THROUGHSAID TUBE AND TRAVERSING THE ENTIRE LENGTH THEREOF, SAID SLOT HAVING AWIDTH LESS THAN SAID SECOND DIAMETER, MEANS FOR ATTACHING SAID ROD TOSAID TUBE, SAID MEANS BEING FIXEDLY ATTACHED AT ONE END TO SAID ROD ANDAT THE OTHER END TO SAID TUBE AT AN ANGULAR DISTANCE OF 60* FROM SAIDSLOT; THE ROD OF SAID FIRST SECTION BEING INSERTED INTO THE TUBE OF SAIDSECOND SECTION SUCH THAT THE ATTACHING MEANS OF SAID FIRST SECTION PASSTHROUGH THE SLOT OF SAID SECOND SECTION; THE ROD OF SAID SECOND SECTIONBEING INSERTED INTO THE TUBE OF SAID THIRD SECTION SUCH THAT THEATTACHING MEANS OF SAID SECOND SECTION PASS THROUGH THE SLOT OF SAIDTHIRD SECTION, AND THE ROD OF SAID THIRD SECTION BEING INSERTED IN THETUBE OF SAID FIRST SECTION SUCH THAT THE ATTACHING MEANS OF SAID THIRDSECTION PASS THROUGH THE SLOT OF SAID FIRST SECTION.